This invention relates to a circuit for driving a switching transistor used in, for example, switching regulators, and in particular, to such a driving circuit wherein the switching speed of the switching transistor is improved.
Voltage regulators of a switching type have been well known in the prior art and have been used in DC power supply devices for supplying regulated powers to various electronic devices.
One or more switching transistors are used in switching regulators and perform turn-on and turn-off operation under control by switching pulses. It is well known in the prior art that switching operation of the switching transistor cannot be effected at a rate higher than a certain speed by the reason of the carrier storage effect of the transistor. That is, when the switching transistor is turned off, current flow through the switching transistor is not stopped immediately but continued until the storaged carrier is consumed. Therefore, since the interval between the turn-off operation and the subsequent turn-on operation cannot be selected to be equal to, or shorter than, the carrier storage time, the switching transistor cannot effect the switching operation at a high repetition cycle. Moreover, the current flow due to the storage carrier results in power dissipation.